Why does their Facebook page delete conversations?

I figuratively stumbled onto this movie's page. It was interesting so I read the comments. I found a conversation one commenter was having about the successful missions into space were based around equations using the conpeenican model. This movies page says they were successful cause of gps programs. I asked simply if the program was around in 1968-9 around the time of the Apollo mission. The page replied with an article. Saying it was in development. I asked about the Soviet Union and he pointed to a god tech they were developed. When I mentioned the satellite didn't launch until 13 years after their first manned launch the conversation was deleted. It's easy to dispute me succesfully especially in this matter. I'm not a smart man. And all I did was ask questions why did this page delete that conversation?